I've just spent the weekend re-installing my rebuilt YB engine into my 1.6 3door sierra shell. It's a group N rally spec shell running a 200block 4x4 engine. I noticed this afternoon that the fuel tank is rotten and has started to weep the tank has a Kevlar composite guard which was hiding this leak. It needed a drain hole so water didn't collect in it. Anyway, I removed the tank and noticed two of the four sender wires are broken(the fuel gauge had not worked properly since I got the car) One is live and the other one is seperate wire with a rubber plug going to a thread next to the sender plug,im guessing this is the earth,which isnt anymore!!! The other two looked like they were cut on purpose!
How many wires does the sender need to make it work properly?
Does the sender talk to the ecu?
It has an L8 ECu fitted.😖

 

Maybe the extra wires are for the low level warning light on the dash

 

Sender does not talk to ECU (well it does to the AWS ECU)

Basically this is the system that provides the low coolant, brake pad, fuel warning lamps etc, being yours is a different shell it may not have this, as only high spec models did.

As said Is suspect the extra wires are for the warning lamp perhaps?

Martin